White-water self-cleaning settling tank



May 24 1927.

J. P. HASS WHITE WATER SELF CLEANING SETTLING TANK Filed Dec. 21. 1925 2 Sheets-Sheet 1 1927. May .L'P. HASS WHITE WATER SELF CLEANING SETTLING TANK Filed Dec. 21. 1925 2 Sheets-Sheet 2 Patented May 24, 1927.

JOHN PAUL HASS, OF INTERNATIONAL FALLS, MINNESOTA.

WHITE-WATER SELF-CLEANING SETTLING TANK.

Application filed December 21, 1925. Serial No. 76,855.

effecting a material saving upon part of a manufacturer.

'It is likewise an equally import-ant object of the invention to rovide a device of the character described in which white water is discharged whereby the pulp content hereof will be effectually and economically removed by settling to the bottom of the tank, whereupon such stock will be immediately and fully removed from the tank, hence preventing its fermentation and avoids ing the floating of the pulp'with its resultant loss ,in the overflowing waste or sewerage white water.

Yet another and equally important object of the invention is to provide the settling tank with means movable along and over the bottom thereof for effectually engaging and removing the settled pulp from the tank bottom and directing it into a discharge means in order that the same will be conveyed from the tank and prevented from accumulating therein.

Other objects of the invention will be in part obvious, and in part pointed out hereinafter. I

In order that the invention and its mode of operation may be readily understood by persons skilled in the art, I have in the accompanying illustrative drawings, and in the detailed following description based thereon, set out one embodiment of the same.

In these drawings:'

Figure 1 is a plan view of the improved settling tank having parts thereof broken Figure 2 is a vertical longitudinal fragmentary section through the same;

Figure 3 is a fragmentary detail in verti-i cal transverse section taken on, a line 3-3 of Figure 2 looking in the direction in which the arrows Point, and

Figure 4 is a fragmentary detail, in longitudinal section showing the mounting of the scraper --bars upon the endless chain and bottom.

Having more particular reference to the drawlngs, in connection with which like characters of reference will designate corresponding parts throughout, the improved settling tank may be stated to comprise a receptacle generally indicated herein by the numeral 1, such receptacle being shown in this embodiment to be of substantiall rectangular formation and provided wlth a rearwardly inclined bottom 2, while white water inlet feed pipes 3 are connected with the upper portion of the forward end thereof and are adapted to discharge into a head box 4 whereby the same may pass or-flow over an overflow wall 5 into the tank proper in the manner clearly indicated in Figure 2; a perforated stilling box or a trough 6 being arranged in fixed relation to the upper portion and inner side of the wall 5 whereby to receive the flow of white water from the head box 4 over the marginal portion of said overflow wall 5; A waste discharge box 7 is fixedl arranged with respect to the outer side an upper end of the rearward wall 8 of the tank 1 and as will be noted, has an outlet trough 7' extended laterally therefrom into communication with any suitable sewerage system, not shown herein, in order that the waste watenmay be effectually conveyed from the settling tank. At this point, it is to be also noted that communication of the tank proper with the discharge box 7 is effected over an overflow wall 9 upon the upper portion of the rearward end wall 8 and by consequence, when the level of white water in the tank reaches a height as indicated in Figure 2, there will be a continual flow of the waste water into the discharge box 7 for discharge from the settling tank.

As means for conducting clear white water from the settling tank for washing and other purposes, an overflow or outlet pipe 10 communicates with an upper portion of the rearward end of one side wall. of the-receptaclel, in a manner indicated in Figure 2, thus allowin such clear white water to be conducted rom the tank, this clear white water of course resulting from the settling of the pulp therefrom onto the inclined bottom 2.

To prevent surging or similar undesirable agitation of'the white water ifany, in the tank 1 and to expedite the settling of pulp therefrom onto the inclined bottom 2, I may and preferably do mount a rearwardly inclined transversely positioned bafile ll'therein, securing the opposite ends of such baffle in a suitable manner to adjacent portions of the opposite side walls of the tank 1; the lower and rearwardly disposed portion of such bathe 11 being arranged in s ace'd relation with respect to the incline bottom 2.

With a view towards providing the rearwardly inclined bottom 2 of the settling tank 1 with means for effectually and positively removing the settled pulp from such bottom and from the tank whereby to avoid its accumulation and resultant fermentation with flotation of particles of the pulp upon the waste or white water, an endless and longitudinally moving scraping or raking device is employed, the same preferably consisting of relatively parallel transversely disposed shafts 12 and 13 journaled in suitable bearings adjacent the inner side or faces of the opposite side wall of the receptacle 1 and fixedly carrying sprocket wheels 14 upon the opposite extremities thereof, as well as upon the intermediate portions of the same in a manner clearly shown in Figure 3; a longitudinally disposed rib 15 being fixedly arranged upon the intermediate ortion of the inclined bottom 2 and exten ed longitudinally throughout the greater portion of its length. Endless sprocket chains 16 are engaged about and movable over the various pairs of sprocket wheels 14 mounted upon the several shafts 12 and 13 and carry thereon, pivotal scraping or raking bars 17, said bars 17 being disposed transversely of the bottom 2 of the tank 1 and positioned in those ways provided between the opposite side walls of said tank and the opposite sides of the longitudinally disposed intermediately placed rib 15. To effectively support the endless sprocket chains 16 throughout their respective lengths during longitudinal movement through the settling tank 1 and to insure proper engagement of the various arms 17 with the inclined bottom 2 at appropriate times, tracks 18 preferably formed of angle iron are secured to the lower portions of the inner sides of the opposite side walls of the tank 1 in parallel relation to the rearwardly inclined bottom 2 and to the upper portions of the opposite sides of the longitudinally disposed intermediately spaced rib 15, these tracks 18 being adapted to receive and to movably support the lower or under sides of the endless sprocket chains 16. The upper sides or portions of the sprocket chains 16 are adapted to be movably supported upon other and similar longitudinally disposed pair of tracks 19, the same being likewise formed of angle iron and having fixed or immovable support with respect to the settling tank 1 through the medium of a plurality of equi-spaced transversely disposed I-beams 20, the opposite ends of which are suitably anchored to adjacent portions of the inner sides of the opposite side walls of said tank 1. be noted that the upper pairs of longitudinally disposed tracks 19 are also arranged in parallelism with the rearwardly inclined bottom 2, while the opposite extremities thereof are bent or curved downwardly as indicated at 21. Likewise, the lower portions of said pairs of tracks 19 are of widths reater than the corresponding portions of the pairs of tracks 18 and consequently upon this, it will be appreciated that with longitudinal movement of the endless sprocket chains 16, the pivotally mounted bars 17 when moving in proximity to the rearwardly incline-d bottom 2 will be permitted to swing by gravity to those downward positions as shown in Figures 2 and 3 thus effecting a scraping or raking engagement with the surface of said bottom 2. However, as the longitudinal movement of the sprocket chains 16 over their respective sprocket wheels 14 continues, the pivotally mounted bars 17 will be moved between the appreciated that the inner or upper bars 17 will be prevented from effecting undue and undesirable agitation of the white water in the settling tank and hence, that the settling of pulp or stock therefrom onto the inclined bottom 2 will be materially expedited. As the various bars 17 become disengaged from the opposite or forwardly disposed ends of the said upp r tracks 19 it is manifest that they will freely swing by gravity and therefore during their sequential passage over the inclined bottom 2, will move into raking engagement with the surface thereof in the manner as is also illustrated in Figure 4. Thus, it will be understood that the pulp or stock settling onto the inclined bottom 2 will be engaged by the scraping bars 17 and will be moved longitudina-lly over the rearward ends of the tank 1.

In order that the settled pulp or stock engaged and moved longitudinally and rearwardly over the inclined bottom 2 may be conducted from the settling tank, a trans versely disposed trough 2 is formed in the rearward end of the Settling tank 1 below In this connection, it is to the surface of the rearward end of the inclined bottom 2 and has a spiral conveyor 23 mounted therein, the carrying shaft of which is journaled in suitable hearings in adjacent portions of the side walls of said receptacle. One end of this carrying trough, indicated for the purpose of convenience by the numeral 24, is extended be 0nd one side Wall for a purpose which wil be presently described.

To provide this scraping device and the spiral conveyor with drive means, a housing 25 is arranged adjacent the rearward portion of one side wall of the settling tank, in the manner indicated in Figure 1, said housing receiving therein the extended end of a conveyor carrying shaft 24 together with the laterally extended end of the shaft 13; the extended end of the shaft 24 passing through a sleeve-like extension 26 suitably supported within the housing 25 and havin communication through an elbow 27 with a stock moving pump 28, said pump being operated from an electrical motor 29 or similar actuating means and having the discharge conduit 30 thereof connected to and communicating with a discharge pipe 3l adapted to dis charge the recovered or settled pulp or stock into suitable or appropriate apparatus in the millli equipped with the improved settling tan A pulley wheel is mountedupon the extended end of the conveyor car ing shaft 24 and has a belt or other suita le motion transmitting device 32 engaged thereover, this device passing over a similar pulley wheel mounted upon a driving shaft 33 adapted to receive 1ts drive or rotary motion through the medium of suitable gearing 34 from a motor or other source 35 mounted in the housing 25. Also, the extended end of the shaft 13 carries a pulley wheel thereupon about which an endless belt or similar motion transmitting device 36 is engaged,

the latter in turn engaging about a second pulley wheel mounted upon the driving shaft 33 in order that rotary motion may be alSO transmitted to said shaft 13, effecting its rotation and the consequent transmission of longitudinal movement to the endless sprocket chains 16 carrying the pivotally mounted bars 17 in order that the latter may be moved longitudinally through the settling tank 1 and over the upper surface of' the rearwardly inclined bottom 2 of said settling tank to effectively remove the settled and accumulated pulp or stock therefrom to the transversely disposed trough 22.'

The operation of the settling tank may be reviewed as follows g White water is discharged into the settlin tank 1, reaching the level as indicated in igure 1 of the drawing, said white water flowing over the upper marginal portion of the overflow wall 5 from the said lTOX 4 into the receptacle proper, by way of the stilling box 6, surging or similar undue agitation of said white water within the tank proper being prevented by the arrangement of the transversely positioned bafile 11. The pulp or stock contained in the white water will settle onto the rear'wardly' inclined bottom 2 of the tank whereupon it is immediately engaged by the rearwardly and longitudinally moving lowermost bars 17 and directed over the rearwardl inclined bottom 2 into the transverse troug 22 whereat the spiral conveyor 23 will function to discharge the same laterally to the outlet port in t e side wall adjacent one end of said spiral conveyor into the sleeve 26, following which the stock pump 28 will serve to move it along and discharge it, under pressure, into the conduit 31 for conveyance to the mill. Due to the fact that the uppermost pivotal bars 17 move to featherin positions when engaged with the oppositely disposed pairs of tracks 19 it will be understood that excessive agitation of the white water within the tank will be avoided.

Manifestly, the construction shown is cap ble of considerable modification and such modification as within the scope of the appended claims, I consider within the spirit of my invention.

I claim:

1. In combination, a tank having a head box, a perforated trough, and an overflow wall between the box and trough whereby a fluid from said box will ass over said wall and drop into said troug a bafile inclinin 0' from a point ad'acent said trou h toward the bottom of sai tank and anen less scraping device having its head portion arranged under said trough and said inclined bafile.

2. In combination, a tank having a head box, a perforated trough, and'an overflow wall between the box and trough whereby a fluid from said box will ass Over said wall and drop into said troug a bafile inclining from a point adjacent said trough toward the bottom of said tank, an endless scraping device having its head portion arran ed under said trough and said inclined ba e, and acombined spiral conveyor and suction device arranged directly below the discharge end of said scraping device.

In witness whereof I have hereunto, set my hand.

J. PAUL HASS. 

